Safety device for elevators



Au 22, 1933. F. L OHLER 1,923,683

SAFETY DEVICE FOR ELEVATORS Filed May 1, 1930 :2 Sheets-Sheet l Aug. 2-2, 1933. F. L. OHLER 1,923,683

SAFETY DEVICE FOR ELEVATORS Filed May 1, 1930 2 Sheets-Sheet 2 Patented Aug. 22, 1933 PATENT QFFifiE SAFETY DEVICE FOR ELEVATORS rrank L. Ohler, Toledo, Ohio, assignor to The Haughton Elevator and Machine Company, Toledo, Ohio, a Corporation of Ohio Application May 1, 193

v Glaims.

This invention relates to safety devices for elevators and more particularly to devices for protecting passengers against too rapid a descent under emergency conditions. It is customary in 5 connection with elevators to provide means adapted to be tripped into action so as to grip guide rails in the sides of the hatchway and to stop the descent of the car as quickly as practicable whenever the descent becomes too rapid,

due to a broken cable or some other cause. It

is also customary to provide a buffer at the bottom 0 the hatchway. It follows that if the car is so. w ere near the bottom of the hatchway when it begins to drop, so that the gripping devices are tripped into action at about the same time as the car strikes the bufier there is a double retardation which stops the car so quickly that there is grave danger or seriously injuring or maiming the passengers.

With the above conditions in mind, it is the object of the present invention to provide a safety device which will have substantially the same effeet under all such emergency conditions, no matter at what point in the downward travel such conditions may arise.

in the present form of the invention, the buffer is mounted on and carried up and down with the car. There is also, of course, a similar bufier carried by the counterweight. Theirame connected with the buffer carries a gripping device which acts quickly and positively when it is tripped, to stop the travel of the buffer and through the medium of the buffer to stop the travel of the car substantially at the same rate that it would be stopped it the buffer struck the bottom of the hatchway.

The invention in its present embodiment will be more particularly explained in connection with the accompanying drawings, in which Figure l is a side elevation of the invention as applied to the bottom of an elevator car.

Figure 2 is a section taken substantially on the line 2-2 of Figure 1.

Figure 3 is an enlarged sectional view of the tripping device.

Figure 4 is a side elevation of the buffer attached to the counterweight.

Figure 5 is a detail sectional view taken on the line 55 of Figure 3.

The invention is illustrated in connection with an elevator car having a platform 5, beneath which are channel bars 6. Beneath these channel bars are secured guide shoes '7, which follow the guide rails 8 in the sides of the hatchway.

Opposed to the elevator car is a counterweight 9 e. Serial No. 449,016

from which a cable 10 extends downwardly about a compensating sheave 11 and thence to the channel bars beneath the car 5.

In mounting the buffer on the elevator car, a frame 12 is mounted on the lower ends of the 0 supporting rods or bars-13 which are secured to the sides of the bars 6 in depending relation thereto. Springs 14 are provided for cushioning the frame 12 and the rods 13 are slidable downwardly with relation to the frame 12 when the 5 latter is stopped. The frame 12 has a yoke 15 at each end which is mounted for rocking movement about the pivot 16 and is provided with guide shoes 17 which follow the guide rails 8.

The buifer comprises a cylinder 18 which has a rocking connection at 19 with the center of the frame 12 and a piston 20 which is supported by a cushioning spring 21 from the channel bars 6. A seat 22 is mounted on springs 23 or other cushioning device at the bottom of the hatchway to'receive the buffer cylinder 18 in case the car overtravels into the pit. The piston 21) is provided with an annular shoulder 24 adapted to rest against a seat 25 secured to the bars-6.

In connection with the invention, provision is made for stopping the downward movement of the buffer and the frame 12, in case an emergency should arise, by means of any suitable gripping mechanism adapted to cooperate with the guide rails 8 in a well-known manner. In the present embodiment, a rock shaft 26 is mounted in the yokes 15 and is provided with a lateral- 1y extending arm 27 which is connected by a line 28 passing about sheaves 29 and 30 located beneath the car to a suitable centrifugally operated trip mechanism of a well-known type, usually located in the penthouse. At each end of theshaft 26 there is secured an arm 31 which, through a spring 32, is adapted to raise a spindle carrying a roller 35 at its upper end. The spindle is normally supported in a boxing 34 formed on the yoke and straddling the guide rail 8. The boxing 34 contains on one side of the rail,

a block 36 having an inclined surface adapted to engage the roller 35 and on the other side of v the rail, a substantially rectangular block 37, integrally connected to block 36 as shown in Figure 5, and adapted to be forced into engagement with the rail as soon as the roller 35 is raised to effect a wedging engagement between the rail and the inclined surface of the block 36. Pins 38 are secured in the block 37 and are engaged by springs 39 to hold the block normally out of engagement with the rail 8.

A buffer 40, similar to the bufier 18, is asso- 0 ciated with the counterweight 9. It is desirable to provide guards 41 in the bottom of the hater-- way to protect the buffer 18 in case it should descend into en agement with the seat 22.

In the eration of the invention, in case the downward movement of the elevator becomes rapid enough to actuate the trip, a pull on the line 28 rocks the shaft and causes the roller to grip the guide rail 8. efore the roll grip is effective to stop the descent, however, the block 37 is first drawn against the rail 8 and the pressure of the springs 39 is exerted to cause side pressure of the shoes 17 against the rail to overcome the inertia of the mass.

Wherever the trip may be actuated, the descent of the frame 12 and buffer cylinder 18 is stopped in substantially the same distance as would be the case if the cylinder 18 should strike the seat 22 at the bottom of the hatchway. Consequently the movement of the and also the descent of the elevator ar are stopped at substantially the same rate, regardless of the point at which sucn stopping occurs, The pivots 16 and 19 permit a rocking movement of the frame 12 in case the gripping action at one end of the frame should take effect more quickly than at the other end. 'This prevents any cramping of the buffer. The er ment of the shoulder 24 with its seat 25 c loss the bufifer action to take place immediately when the gripping action takes place between the ends of the yoke 15 and the rails 8 at the side of the hatchway. In starting the elevator car on its upward movement, the springs aid in overcoming the inertia of the buffer and its frame. They also aid in releasing the gi'os to reset them for normal operation. The spring 2 aids in overcoming the resistance of piston 20 when is reset.

It is to be par 'cularly noted that the operation of my invention res l in a buffer stop at any point in the hatch-way w it be tripped, with a more uniform and easier retardation than it is possible to obtain with a mechanical gripping device alone. The action of the buffer may be accurately adjusted before it leaves the manufacturing plant whereas a purely mechanical gripping device can never be adjusted so that its action will be ccurately controlled.

While I have shown and d-scribed specifically one embodiment in which the invention inay be embodied, it is obvious that the may be considerably modified without departing materially from the scope of the appended claims.

What I claim is:

1. The combination with an elevator car and hatchway, of a buffer, a frame having a r cking connection with the buffer, means connecting said buffer and frame to the car, and means mounted on the outer ends of said frame for gripping the sides of the hatchway under emergency conditions so that thebuifer will have substantially the same effect in stopping the car as when the buffer strikes the bottom of the hatchway.

2. The combination with an elevator car and hatchway, of a buffer including a cylinder and piston, a frame having a rocking connection with said cylinder, direct connections between the car and said piston and frame respectively, whereby the buffer will normally travel with the car, and means carried by the frame for gripping the sides of the hatchway at the ends of the frame under emergency conditions to render said buffer operative to stop the car.

3. The combination with an elevator car and hatchway, of a buffer including a cylinder and piston, a frame having a rocking connection with said cylinder, direct connections between the car and said piston and frame respectively, whereby the buffer will normally travel with the car, and means carried by the frame for gripping the sides of the hatchway at the end of the frame to stop the buffer under emergency conditions so that the buffer will have substantially the same effect in stopping the car, regardless of the point at which such emergency conditions occur.

l. The combination with an elevator car and hatchway, of a buffer including a cylinder and piston, a frame having a rocking connection with said cylinder, supporting members secured in depending relation to the bottom of the car with said frame normally resting thereon, said cylinder being supported by said frame, the piston being connected to the car, and means carried by the frame for gripping the sides of the hatchway at the ends of the frame for stoppin the downward movement under emergency conditions, said supporting members being slidable downwardly with respect to said frame when the latter is stopped.

5. Thecombination with an elevator car and hatchway, of a buffer including a cylinder and piston, a frame havin a rocking connection with said cylinder, supporting members secured I:

in depending relation to the bottom of the car and provided with cushioning means on which said frame normally rests, said cylinder being supported by said frame, a seat on the underside of the car, yieldable means for holding the piston against said side, and means carried by the frame for gripping the sides of the hatchway at the end of the frame for stopping the downward movement thereof under emergency conditions, said supporting members being slidable downwardly with respect to said frame when the latter is stopped.

FRANK L. OI-ILER. 

